1. Field of the Invention
The present invention relates to a composite filter and a radio equipment using the same and, more particularly, to a composite filter including a surface acoustic wave filter and a LC filter, and a radio equipment using the same.
2. Description of the Related Art
FIG. 7 is a RF block diagram of a portable telephone terminal equipment which is a general radio equipment. The portable telephone terminal equipment shown in FIG. 7 is of a single band type which operates in a single frequency band range of 800 MHz, 1.5 GHz, and so forth contains an antenna ANT, an antenna duplexer DPX, a sending radio signal section Tx, a receiving radio signal section Rx, and a synthesizer section SYN. The input of the sending radio signal section Tx is connected to a modulation section MOD, while the output of the receiving radio signal section Rx is connected to a demodulation DE. The sending radio signal section Tx is made up of a high power amplifier PA, a band pass filter F1, a low pass filter F2, and a mixer MIX, and has a function of outputting a receiving signal, received from the modulation section MOD, through the antenna duplexer DPX to the antenna ANT. On the other hand, the receiving radio signal section Rx is formed of a low-noise amplifier LNA and band pass filters F3, F4, and has a function of outputting a receiving signal, received from the antenna ANT, through the antenna duplexer DPX to the demodulation section DE.
Conventionally, the amplifiers PA, LNA, the mixer MIX, the antenna duplexer DPX made up of a dielectric filter, and the respective filters F1 F4, which are chip components, are mounted on a circuit substrate made of glass epoxy resin, ceramics, or the like, though not shown.
In case of above portable telephone terminal equipment which is a conventional radio equipment, its respective components are intensively integrated in the form of chips.
However, there has arisen a problem that the integration brings an increase in the number of components, complicated assembly process, and so forth.